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HODIERNA (Odierna); Giovanni B.; 1597-1660; ITA

Following theology studies, Hodierna got interested in astronomy among various other scientific fields. He studied Jupiter's satellite, Saturn and the 3 comets of 1618-1619 with a refractor built in the same manner as GALILEO (power of 20x). His most important discoveries were in the deep sky: he found 40 "nebulae" published in 1654 ("De Admirandi Coeli Caracteribus", Palermo, 1654) among which 19 are true objects. He described a rough classification: "Luminosae" (resolved into stars with naked eye), "Nebulosae" (nebulous with naked eye but resolved at the telescope), "Occultae" (nebulous even for the telescope).